Expired European patentEurope
Process for the separation of sulphuric acid from the sulfoxidation product obtained by reacting paraffins with sulphurous anhydride, oxygen and water in the presence of ultraviolet light
EP 0037883 B1 · Applicant: CHEMISCHE WERKE HÜLS AG
Overview
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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 14, 1981 and granted March 23, 1983. A European patent lasts at most 20 years from filing, so its term ended February 14, 2001.
- A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by August 14, 2006.
- We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledFebruary 14, 1981
PublishedOctober 21, 1981
GrantedMarch 23, 1983
Term endedFebruary 14, 2001
Application numberEP 81101047
Classification (CPC)C07C303/42
Timeline
Timeline From EPO dates
Sources & verification
Official EPO records
Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.